A Calibration Method for Magnetic-Field Injection Probes by Separating Electric-Field Response

In near-field scan immunity (NFSi) testing of integrated circuits (ICs), a magnetic-field injection probe (MFiP) is typically used at a certain height above the IC to perform immunity scans. This method can accurately locate sensitive areas and obtain sensitivity thresholds. The obtained sensitivity threshold depends on the accuracy of the probe factor of the MFiP. However, the calibration procedure for the MFiP is affected by the output of the electric-field response, thereby impacting the calibration accuracy. This communication proposes a phase measurement-based calibration method that can separate the magnetic-field response and the electric-field response in the calibration procedure. To validate the feasibility of this method, an improved calibration procedure is discussed in conjunction with a designed ultrawideband MFiP, demonstrating that this calibration method can achieve a more accurate probe factor.